Electrical outlet with movable closure



July 11, 1950 P. E. HAMILTON ELECTRICAL OUTLET WITH MOVABLE CLGSURE Filed Sept. 14, 1948 Patented July 11, 1950 UNITED STATES PATENT OFFICE ELECTRICAL OUTLET WITH MOVABLE CLOSURE 2 Claims.

This invention relates to an electrical outlet and more particularly to a safety outlet for the reception of plugs on extension cords.

In the usual electrical outlet, electrical con ductors connected with the source of electricity are situated at the base of recesses which are continually open when the outlet is not in use. The recesses are spaced for the reception of the plugs which make contact with the electrical conductors at the base of the recesses. In these conventional fittings, which most often are located slightly above floor level, dirt is free to pass into the recesses. Moreover, it is possible that hairpins and other metallic objects may be inserted in the recesses, for example by young children, and shook the child or cause a short circuit.

In order to overcome the objections to the ordinary outlets, outlets have been designed with a rotating shutter which is normally in a position to close the recesses and prevent the entrance of foreign materials. The safety outlets of this type have heretofore been rather difficult to assemble which adds greatly to their cost of manu- 'facture. Ordinarily the outlets are made of relatively low cost materials and sold at a low price. Clearly a complicated structure which is dimcult to assemble cannot be commercially successful.

It is, of course, necessary to construct most parts of the outlet of non-conducting materials. The materials usually employed are various plastic compositions which in most cases have low strength, as compared with metals. It is, there fore, desirable to provide a safety outlet in which the parts thereof are subjected to minimum strains.

It is an object of this invention to provide a safety electrical outlet which closes the recesses in the female electrical connection when the outlet is not in use.

Another object of this invention is to provide an electrical outlet of the safety type which may be easily manufactured and sold at a low price.

It is also an object of this invention to provide a safety electrical receptacle in which the parts are thoroughly insulated and protected to eliminate any possibility of one using the receptacle receiving a shock.

Still another object of this invention is to provide a safety outlet having a, shutter normally closing the recesses of the outlet adapted to move in either direction to a position in register with the electrical conductor in the outlet.

With these and other objects in view which will become apparent in the detailed description following, this invention resides in an electrical receptacle having electrical conductors in a base member. A shield lies over the conductors having openings in alignment with the conductors and rotatably supporting a shutter having openings normally out of register with the openings in the shield. The shutter may be rotated in ither direction to a position in which the openhgs therein are in register with the openings in the shield.

In the drawings:

Figure l is a top plan view of the completely assembled electrical outlet comprising this invention;

Figure 2 is a vertical sectional view along section line 2-2 in Figure 1 illustrating the assembled outlet;

Figure 3 is a horizontal sectional view along the section line 3-3 in Figure 2 showing the shield on which the shutter turns;

Figure 4 is also a horizontal sectional view taken along the section line 3-4 in Figure l illustrat ing the position of the conductors in the outlet base of the outlet; and

Figure 5 is an exploded perspective view of the retainer shutter and shield of the outlet described herein.

For purposes of illustration, this invention is described with reference to a conventional household outlet having two receptacles for plugs from extension cords. Referring to Figure 2, the electrical outlet, indicated generally by I, is attached to a bracket 2 for securing in place in any suitable container 3 in a wall or floor of a building. The container 3 and outlet are covered by a cover plate 4 of the conventional type.

The electrical outlet I has a base member 5, illustrated in section in Figure 2 and in plan in Figure 4, to which the bracket 2 is secured by screws 5. The base 5 has grooves I extending longitudinally thereof and opening through the side walls 8 of the base for the reception of conductors 3 and Iii. The conductors 9 and I!) may be provided with screws II or other suitable means for connection with the wires from the source of electricity. Grooves l are separated by a ridge l2 extending centrally through the length of the base in which there is a central cavity l3 communicating with the outer surface of the base 5 by means of a hole l4. On each side of the cavity l3 are round recesses l5 and I6, having grooves in their lower ends, serving as journals in which the shutter of the outlet turns in the manner hereinafter described.

Resting on the upper surface of the base 5 is a shield I! which is essentially a flat strip of quickly assembled by unskilled workers. the bracket 2 has been attached to the. base 5 insulating material having openings [8, l9, and 28 positioned in alignment with recess l5, cavity 13, and recess l6, respectively. The shield I"! has slots 21 positioned directly over the conductors 9 and IE to allow contact of the prongs of a plug with the conductors. The ends of shield I? are depressed to form channels 22. These channels are terminated by shoulders 23 on the shield which limit the rotationof the-shutter- A pair of disc-like. shutters 25 having hubs. 2B are supported on the upper surface of the shield with the hubs extending through the openings: i8 and 2B. The lower end of the hub is grooved at 27, as illustrated in Figure 2; for engagement. with a torsion spring 28. The torsion spring 28 rests on the recesses l5 and I6 and engages the.-

grooves in the bottom of those recesses. A pair of slots 29 are positioned in the'shutterfor alignment with the slots 2! in the shield l1 and.con:- sequently with the electrical conductors 9 and H3 in. the base of the outlet. In their normal position, illustrated in the drawings, however, the slots 29 are angularly disposed 90 from the position of the slots 21 and. effectively close the openings of the'outlet.

Each. of the shutters 25 has an. annular shoulder 38' extending around its periphery from which alug 32 extends. downwardly. When the shutter 25 is resting on the upper surface of the shield H, the lugs 32 travel in the channels. 22. Rotation of the shutters 25 is limited by engagement-of thelug 32withone of the shoulders. 23 at the end of the channels 22. When the shut.- ter is in its normalposition, thelug lies midway between the shutters.

A retainer 33 having openings 34 in raised collars 55 is adaptedto fit over the shutters. 25 and hold them securely, but rota-tably, in placeon the shield H. The annular shoulders 3110f theshutters 25 are of larger diameter than the openings 3'r a nd' engage the lower surface of the retainer 33, as is best illustrated in Figure 2, to prevent movement of the shutters 25from the. shield H. The retainer QE-has side walls Siidepending from its upper surface to the upper. edge of the side walls 3 or" the base 5 to enclose the shutters 25 and the shieldci'i.

Extending downwardly from a depressed neck 31 between the collars 35 is a post. 38 positioned toenter the cavity 13 or the base 5 of the outlet. The post 38 is drilled and tapped throughout its length for the reception of a screw- 42 which holds the retainer 33 firmly against the base: 5 to give a rugged, unitary structure. In order to further increase the rigidity of the. structure, the retainer may be equipped with arms 39-at its ends which engage grooves 40 in the shield H and M. in the base 5.

The assembly of the outlet is completed after the base, shield; shutters and retainer have-been assembled and secured in position by means of the. bracket 2 by placing a conventional cover plate 4; over the retainer. The cover-plateis'provided with openings Stand Mpositioned to receive the collars 35 of the retainer 33. The cover plated is also drilled at 5 for the reception. of a screw 46 which enters the post 38 to hold the cover plate firmly in position.

The electrical outlet described herein. maybe After by means of screws 6, the torsion springs 28 are dropped into recesses and IS. The shield I1 is placed. in position with the openings l8 and in register with the recesses l5 and. L6,. and

the shutters 25 are then placed on the shield with the hubs 2t entering the openings I8 and 20 and engaging the torsion springs 28. The retainer is dropped into position and the screw 42 is tightened to hold the retainer, and consequently the shutters 25 and shield 11, firmly against the base 5. The outlet is then fixed in position by means of screws ill which engage the bracket 2 and the cover plate is then tightened in place by means of screw 361. The complete assembly of the outlet takes but a few seconds and contributes greatly to the low cost of production of the outlet.

The operation of the outlet is believed to be clear from the description of its structure. The

prongs. of. a plug are placed in the slots 29 of the shutters 25 and the shutter is turned in either directionuntil the slots 29 are in alignment with the slots 2i of the shield at which point the prongs of the plug are free to slide into contact with. the electrical conductors 9 and ID. The proper alignment of the shutter 25 and theshield IT is aided by the provision of the walls 23 which limit the rotation of the shutter to the proper position for alignment of the slots. It will be noted that the shutter 25 is free to turn in. either direction for. the alignment of the slots therein with. the slots in the shield. It is consequently impossible for one to break the relatively weak lug on the shutter by turning. it in the wrong direction. I When the plug is removed from the outlet, the spring. 2 8 urges the shutter 25 to its normalposition. At this position the slots in the shutter are out. of alignment. with the slots in, the shield, and the conductors 'ancl iii are covered. While. this invention has been describedindetail-with reference to. specific examples, it is. to be understood that the invention is not limited to those details but falls within the scopeoftlie appended claimsr.

I claim:. 1....An. electrical receptacle comprising an. insulating. base having electrical conductors therein, a. cavity in the center of the base,..a grooved recess in the base, a shield onthe base having. holes therein overlying the cavity and rec.ess,.slots. in the shield in alignment with the electrical conductors, a shutter rotatable on the shield, slots in. the shutter spaced for alignment with theelectrical conductors, a hub on the shut.-

er adapted to extend into the recess in the base and about which the shutter rotates, a torsion spring in the recess engagingtheshutter and the base urging the shutter to a normal position with. its slots out. of register withthe shield, a retainer overlying the shutter having a post drilled" and tapped throughout its length. extending therefrom into the cavity in.the base,. said retainer engaging the shutter to hold. itagainst the-shield, a cover plate over the retainenscrews securing the cover plate. and base to the post, and arms on ends of the retainer engaging grooves in the. shield and base.

2. An electrical. receptacle comprising an. in sulating base. having electrical conductors therein, a cavity in the center of the. base, a grooved recess in the. base, a shield on. the. base having holes therein. overlying the cavity and .recess,. slots in.the shield. in alignment with the electricalconductors, a shutter. rotatable on. the shield, slots in the shutter spaced for alignment with the electrical. conductors, a hub on the shutter adapted. to. extend into the recess in the. base and about. which. the. shutter rotates, a lugon the shutter and shoulders on the shield limiting rotation of the shutter, a torsion spring in the recess engaging the shutter and the base urging the shutter to a normal position with its slots out of register with the shield, a retainer 6 overlying the shutter having a drilled and tapped post throughout its length extending therefrom into the cavity in the base, said retainer engaging the shutter to hold it against the shield, a cover plate over the retainer, screws securing the cover plate and base to the post, and arms on ends of the retainer engaging grooves in the shield and base.

PHILIP E. HAMILTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,989,693 Hubbell Feb. 5, 1935 1,989,890 Slade Feb. 5, 1935 2,154,160 Hamilton Apr. 11, 939

FOREIGN PATENTS Number Country Date 434,078 England Aug. 26, 1935 467,936 England June 25, 1937 684,289 Germany Nov. 25, 1939 

